//
// Created by jsjxsy on 2022/9/1.
//vector嵌套
//
#include <vector>
#include <iostream>
using namespace std;
int main() {
  vector<vector<int>> v1;
  vector<int> v11 = {1, 2, 3, 4, 5};
  vector<int> v12 = {6, 7, 8, 9, 10};
  vector<int> v13 = {11, 13, 15, 17, 19};
  vector<int> v14 = {12, 14, 16};
  v1.push_back(v11);
  v1.push_back(v12);
  v1.push_back(v13);
  v1.push_back(v14);
  int i = 1;
  for (vector<vector<int>>::iterator it = v1.begin(); it != v1.end(); it++) {
    cout << i << " : ";
    for (vector<int>::iterator vit = (*it).begin(); vit != (*it).end(); vit++) {
      cout << *vit << ", ";
    }
    cout << endl;
    i++;
  }
  return 0;
}
